Bike firing on 3 cylinders

[mikesaa309]

I'm getting quite annoyed, I have a bandit 600 1997 model and the other day i started it up and it's only running on 3 cylinders but once I get to around 5 to 6,000 rpm the number fourth cylinder starts firing until the revs drop again.

After checking every spark plug was making a spark I found there was a chunk of plastic missing from the cap on number 4 cylinder and was tracking out obviously. So as the original caps are about 21 quid each from wemoto and other places, I got a patterned Cx500 cap from David Silver Spares. This worked for a while but then went back to 3 cylinders again.

Used mutlimeter and I'm reading between 11-15k ohms for all the spark plug caps (including the broken one) but the cx one Is giving a negative number. So I swapped it for the original one of my dads cx500 which is reading 4-5k ohms on the multimeter and still not firing. Dad also tried using the patterned cx one on his bike and it runs and performs as usual.

Using the multimeter I put the prongs of the multimeter into cylinder 1 and 4 sparkplug caps to check and it's reading 15k ohms and same with the caps off and putting the prongs straight into the HT leads and still got 15k ohms. I can't find any solid reliable information on what reading I should be getting but from what I found the spark plug caps should only be reading between 5 to 10 ohms. (multimeter set on 20k ohms for each test I did btw).

Anyone know the Ohms reading I should be getting?

[MCN.]

Hi sprocket

[Nobby the Bastard]

Typically, you don't lose 1 cylinder on a modern in -line 4, but two becuase they all work by wasted spark. The only time you would is if the gap on the spark plug is completely closed.

Have you checked which exhuast pipes are getting hot (from cold) when you start it?

Still think you're a fucking twat, btw.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[nowhere.elysium]

[Nobby the Bastard]

[nowhere.elysium]

[WD Forte]

negative resistance on the CX cap eh?
that's a neat trick.
keep talking bollocks about the electricals to it
it'll soon give in and run properly just to get you to STFU
____________________
bikers smell of wee

[Pol Anorl]

Im not sure what ive just read.. but i wish to exit the internet now.

Diagnostics 101 has been thrown out the window and the rule book has been chewed up and spat out.
____________________
GOOD GAME BODYGUARD: https://i.imgur.com/8WePGgf.jpg
20:30:37 Pyro.: I don't sort of like men, I take every advantage to choke on dick.
Jewlio Iglesias: You live in Liverpool - Chances are, the front door has already been kicked off the hinges

[andyscooter]

so

Suzuki one was expensive

so you bought one for a Honda that was from a smaller engine so possibly not designed for as much currant

and it doesn't work

what do you think may be wrong
____________________
gilera runner vxr200 (chavped)
if its spelt wrong its my fat fingers and daft auto correct on my tablet

[talkToTheHat]

NGK aftermarket plug caps? I'm sure you can find some at 10kOhm. Negative resistance means either your multimeter is not calibrated (compare to probes touching each other) or the plug is working as a battery, if so clean any corrosion off and apply a water displacer.

Friend's clio had similar problem with damaged plug cap, fixed with cheap aftermarket plug cap and ht lead pulled from the wreckers.
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Bandit. does. everything.

[WD Forte]

On CX plug caps
The original caps had screw in resistors ( 4-5K as i recall) fitted
which were only there as a concession to RF interference.

The resistors often rotted and turned to black dust over the years so
many owners swapped them for patterned caps which were
cheaper and straight through, ie non resistor as well as virtually trouble free.

All the ones I've had did not have the magical negative resistance
just the very low resistance you'd expect from a short peice of brass.
____________________
bikers smell of wee

[talkToTheHat]

Indeed the diagnostic behaviour suggests the HT lead might be damaged or something is wrong with the coil.

If there is significant current flowing through the high voltage size of the ignition, I'd panic. Current should be small and size of 10k resistor is negligible compared to about 0.8mm of fuel-air mixture.
____________________
Bandit. does. everything.

[mikesaa309]

knew I shouldn't have come back here for help...

After checking all spark plug caps and they all read 13k ohms but cx one reads 4k ohms I've found a original suzuki bandit sparkplug cap from a breaker and just waiting for it to arrive in the post.

[MCN.]

[UrbanRacer]

lol at this sh!t